# Labor --- **Labor** is the natural phenomenon where a pregnant person's body undergoes a series of coordinated involuntary muscle contractions to give [[childbirth|birth]] to a baby. Labor begins with the onset of (true) uterine contractions and ends with the delivery of the [[placenta]]. usually begins between 38-42 weeks gestation we don't know *exactly* why labor starts (as in, what triggers it physiologically), other than it is probably due to multiple factors such as: - Uterine stretch (increases receptivity of oxytocin receptors on the uterus) - Change in estrogen-progesterone ratio (estrogen becomes more dominant, which enhances contractility and increases oxytocin receptors) - happens throughout pregnancy but exponentially at labor - Increase in prostaglandin production by the amnion and other uterine tissues, which enhance cervical ripening - same as oxytocin receptors - Fetal maturation may increase prostaglandin activity and the production of hormones that lead to uterine contractility - Release of endogenous oxytocin (nipple stimulation, orgasm) ## Sterile Vaginal Exam A **sterile vaginal exam** or **SVE** is a procedure used during [[labor]] to measure dilation, effacement and station of the baby. It is reported in the format "dilation/effacement/station”. For example, "2/50%/-2" or "8/90%/+1". Sometimes descriptors of the cervix’s consistency and position are added to complete a Bishop's score. Station measures how low down the baby is (hopefully their head) in the pubic bone. 0 is the ischial spine • Do as few as possible in labor Think: will the information change the plan? • As "sterile" (clean) as possible Between contractions • Assess: • Effacement • Dilation • Station/Fetal position • Bishop score if indicated >[!health] Trauma informed care > Cervical exams are extremely intimate and often uncomfortable or even painful. Make sure to practice [[trauma informed care]] and seek active and ongoing consent with every exam. Laboring patients have every right to decline an exam for any reason. ## Stages of Labor The stages of labor are the first, second and third stage, though it can be helpful to consider the "prodromal" stage that proceeds labor and the "fourth" stage that follows the delivery of the baby and placenta. ### Prodromal Stage The **prodromal** stage isn't really a stage of it's own, but is the period of time that proceeds "true" labor. This phase lasts for a few days or even weeks before labor really kicks off. During this time the parent might feel: - **lightening** - the baby drops down into the pelvis, "lightening the load" from the abdomen and getting ready to be born - 1-3 pound loss of weight from fluid loss from sweating - a **burst of energy** and "nesting" behavior - the mucous plug (diagram: [[cervix with mucous plug.png|mucous plug]]) falls out, leaves a "bloody show" or a one time discharge of bloody mucous - sometimes, but not as often as Hollywood may have you think, the [[amniotic sac]] will rupture or "water breaking" - the [[cervix#Cervical Changes During Labor|cervix]] begins to "ripen" or get ready to open up - "ineffective" or "prodromal" **contractions**, referred to as **Braxton-Hicks** contractions: | | Prodromal Labor Contractions | Effective Labor Contractions | | ------------------------------------------- | ----------------------------------------------------------- | ------------------------------------------- | | **Rhythmn** | unpredictable<br>vary in intensity and frequency | close together<br>at regular intervals<br> | | **Progression**<br>(in intensity/frequency) | no | yes | | **change during activity** | go away with activity, or a warm bath, or just on their own | only continue or even increase in intensity | | **effect on cervix** | minimal | dilates and effaces it | ### First Stage (Dilating & Effacing) The first stage of labor can last up to 20 hours, and starts with early, not-very-effective contractions and ends when the cervix is fully dilated and effaced. It is sometimes helpful to think of this phase in two sub-phases, the latent stage phase and the active phase. The **latent phase** or **early phase** takes some time, and can last up to 20 hours. Over this time contractions transition from ineffective ones like in the prodromal phase to effective ones that change the cervix. The **active phase** of labor starts when the cervix is about 6cm and ends when we are fully dilated (10 cm) and effaced (100%). This stage has definitely effective and intense contractions that last up to a minute to a minute and a half and are frequent - active - 6-10 cm and 100% effaced - intense contractions that can even overlap - 60-90 seconds - every 0.5-2 minutes - amniotic sac usually ruptures at this point if it hasn't already "Effective labor contractions" pull the cervix so it gets thinner (effaces) and opens up (dilates) - get the show going - regular - progressively stronger - increase in frequency - **cause cervical change** - effacement (0-100%): shortening and thinning of the cervix (from the external to internal os) - dilation (0-10 cm): opening of the cervix First stage •From the onset of regular contractions/cervical change to 10 cm dilation of the cervix - broken into latent, active, and sometimes even "transition" (like, the last couple cm) We usually start using a [[fetal heart monitoring|fetal heart monitor]] at this stage, just to keep an eye on how the baby is doing. ### Second Stage (Pushing) starts with the mucus plug falling out ("bloody show") or rupturing of the amniotic sac ("water breaking"), starts true labor contractions. Not to be confused with **Braxton-Hicks** or **practice contractions**. - Second stage (pushing stage) - fully dilated and effaced and totally ready - 5 p's - power (2: involuntary contractions, and parental pushing efforts during the second stage) - forceful contractions which helps expel the passengers - Normal labor is characterized by regular, involuntary contractions, progressively getting longer, stronger and closer together - 4 phases of a single contraction: - Increment —contraction begins in the fundus and radiates over the body of the uterus - Acme — maximum intensity - Decrement — gradual decrease - Rest — reduction in time between contractions - how to assess contractions - Frequency — time from beginning of a contraction to the beginning of the next. Usually expressed in minutes. - Intensity — strength of contraction (mild, moderate, strong) - Duration — length of contraction (measured in seconds) - Effectiveness — measured as effacement, dilation, pattern of dilation and fetal descent - Prolonged breath holding and forceful pushing efforts have been associated with fetal hypoxia and acidosis ("closed glottis pushing"). - Directed pushing is associated with increased perineal tears. - No significant difference in the length of second stage has been found with directed pushing in research to date - When possible, encourage spontaneous, self- directed physiologic approaches to pushing during second stage labor - Perception (how it feels): - Premature: may feel like back soreness or menstrual cramps - Term: starts in lower back and radiates around to the front of the belly - passenger (3: baby, cord, placenta) - size - attitude (how it's flexed) - normal is chin to chest, rounded back, flexed arms/legs - this is the smallest diameter baby ("Suboccipitobregmatic diameter") - Refers to the degree of flexion of the fetal body - Normally, a term baby is well flexed, which facilitates birth - Variations: limp (premature), very extended (military, neuro damage) - usually this corrects itself - fetal lie - longitudinal lie is ideal - spines are alined - transverse and oblique are not ideal - presentations - cephalic is head first (good) - breech (bottom first) (bad) - more common in preterm, because the baby is smaller and the head hasn't flipped down yet - shoulder - fetus makes positional changes during labor ("The cardinal movement of labor") - moves to the fetal station - then the shoulders flex - then it can squeeze though, and it extends it's head extends - passageway - route through bony pelvis - getting the cervix out of the way - baby's head must navigate with their bigass head - Pelvic molding may also occur due to relaxation of the ligaments (hormone: relaxin) - Can try to move the sacrum back with upright or squatting positions - Cervical swelling can occur when pushing occurs too early (typically client should push after 10 cm). - Swelling decreases the diameter of the passageway - Generally, does not improve and cannot be reversed - position - the parent's positioning that helps the fetus move through these cardinal movements of labor - psyche - the psychiatric health of the laboring person, which has a big actual effect on the experience - A laboring person's psychological state and behavior change during labor and provide important clues on labor status and their needs for support - The nurse assesses all of the following in order to fine tune their physical and psychosocial care of the patient and their support person(s). - Verbal interactions - Body language - Perceptual ability (ability to take in information from their environment) - Discomfort level Second Stage •From the *full dilation* of the cervix to the birth of the baby now the cervix is out of the way. now we coach for "efforts to expel the baby" - can also be broken into three stages (which aren't always *linear*, but generally speaking) - first stage, there may be periods of rest - active stage - not really a chance for a rest in this phase. - transition phase - strong expulsive efforts - **Ferguson's Reflex** - happens at like, +4, +5 - feels like they have to have a bowel movement - Pushing or bearing down efforts assist with descent of fetus — abdominal muscles are used to increase intra-abdominal pressure - Prolonged breath holding and forceful pushing efforts have been associated with fetal hypoxia and acidosis ("closed glottis pushing") - but mom has to breath too, so closed-glottis does happen and it's probably fine - EVERY TIME the uterus is contracting, the fetus is holding it's breath - - Be aware of the fear-pain-tension-cycle - increased fear increases a perception of pain, which increases fear which sends it on a spiral - human intervention in labor is shown to improve comfort Problems in the Second Stage [[second stage dystocia]] ## Third Stage - third stage - expulsion of the placenta - uterus contracts and the placenta separates from the uterine wall Third Stage: •From the birth of the baby through the birth of the placenta Placental expulsion usually occurs within 5-15 minutes of birth 30 minutes = retained placenta Provider keeps mild tension on cord ("gentle traction") and waits signs of separation we don't want to tug too hard, because that can avulse the cord. After birth of placenta, provider will examine it Is it complete? Any fragments appear missing? 3-vessel cord? Evidence-Based Practice: In the absence of heavy bleeding, there is no hurry to deliver the placenta. It is normal and safe, if there is no bleeding, to wait up to an hour, checking for separation periodically. You will seldom see this in hospital practice. [[placenta|retained placenta]] - an emergency because it's still releasing hormone (progesterone) to keep the uterus in place, but we *want* it to contract and clot and close up, and healing that wound - we can do a manual retrevial ## "Fourth Stage" - "fourth stage" - adaption to blood loss - lactated ringers - uterine involution - return to pre-pregnant state Fourth Stage: •From the birth of the placenta through first 2 hours of recovery Immediate cord clamping was an intervention instituted in the early 20th century without evidence, but it became traditional "Delayed cord clamping ": definitions vary (1 min, 3 min, 3-5 min) Many providers wait until cord stops pulsing • Leads to better iron stores at one year of life - May lead to higher risk of hyperbilirubinemia (NRP/AAP, 2012) • May not be possible if neonatal resuscitation is required • Particularly important for preterm babies Ferguson's reflex is the involuntary urge to push occurs when the head descends & stretches receptors in posterior vaginal wall What are contractions like during each phase of second stage? What are the typical vocalizations and behaviors during each phase of second stage? From "true-contractions" to delivery it takes about (can vary a *lot*): - 12-18 hours for a first time pregnancy - 6-9 hours for a subsequent pregnancy ## Problems With Labor • People experiencing dysfunctional labor are at risk for uterine rupture, infection, severe dehydration, and postpartum hemorrhage • The fetus is at increased risk for hypoxia and NICU admission • A long and difficult labor also can have an adverse psychologic effect on the patient, partner, and family • People giving birth now are older and heavier, both factors associated with longer labors Nursing Considerations Positioning • Discouraging movement or restricting labor to the recumbent positions can increase the incidence of dysfunctional labor • Work with gravity, encourage upright positioning and frequent position changes Psychologic responses • Pain and the absence of a support person are often related to dysfunctional labor • Confinement to bed and restriction of movement can be a source of psychologic stress • Anxiety can inhibit cervical dilation and result in prolonged labor and increased pain perception (Fear-Tension-Pain Cycle) • Anxiety causes increased levels of stress-related hormones (e.g., B-endorphin, adrenocorticotropic hormone, cortisol, and epinephrine) • These hormones act on the smooth muscles of the uterus, reducing uterine contractility Precipitous Labor • Labor that lasts less than 3 hours from the onset of contractions to the time of birth (around 3% of births) • Not usually associated with significant maternal or infant morbidity or mortality • Can be caused by placental abruption, uterine tachysystole, and recent cocaine use • Complications can include uterine rupture, lacerations of the birth canal, amniotic fluid embolus (AFE) (anaphylactoid syndrome of pregnancy), and postpartum hemorrhage caused by uterine atony • Fetal complications include hypoxia caused by decreased periods of uterine relaxation between contractions, and, in rare instances, intracranial trauma related to rapid birth **patient experience** • Often describe feelings of disbelief that their labor began so quickly, alarm that their labor progressed so rapidly, panic about the possibility they would not make it to the hospital in time to give birth, and finally, relief when they arrived at the hospital • Frustration when nurses did not believe them when they reported their readiness to push • Progress can be so rapid they may have difficulty remembering the details of their labor and birth • Should be provided with an opportunity to discuss their labor and birth experiences with caregivers who were present ___